The present invention relates to a pneumatic air intake throttle valve control device for a diesel engine for pneumatically controlling an intake throttle valve therein operated at engine idle speed.
Recently, diesel engine vehicles, particularly passenger cars, have become more popular due to their economic advantages. However, vibration and noise produced by diesel engines have been problematic. Particularly, the engine idle speed torque fluctuations, that is, angular velocity fluctuation during a single engine cycle, have been remarkably high in comparison with gasoline engines. This is one factor causing the large amounts of noise and vibration.
In view of the above noted defects, an object of the present invention is to provide an intake air throttle valve control device in which at idle speed or for no-load operation of the engine the air intake is controlled while at the same time the amount of throttle opening is controlled in accordance with exhaust pressure, engine water temperature, intake pressure and the like.